To-Complete Performance Index (TCPI): The Complete Guide
What is To-Complete Performance Index (TCPI)?
The To-Complete Performance Index (TCPI) is a project management metric that measures the cost performance efficiency required to complete the remaining work within the available budget. It is a forward-looking indicator that helps project managers determine if the current performance trend is sustainable for successful project completion.
Why TCPI is Important in Project Management
TCPI serves as a critical early warning system for project managers by:
- Providing a clear efficiency target needed to stay within budget constraints
- Helping teams understand if current performance is sufficient for project success
- Allowing for proactive decision-making when projects are at risk of budget overruns
- Facilitating realistic conversations with stakeholders about project financial health
- Supporting data-driven corrective actions
How TCPI Works
TCPI is calculated using the following formula:
TCPI = (BAC - EV) / (BAC - AC) or TCPI = (BAC - EV) / (EAC - AC)
Where:
- BAC = Budget at Completion (the original total budget)
- EV = Earned Value (value of work completed)
- AC = Actual Cost (actual money spent)
- EAC = Estimate at Completion (revised total cost projection)
The first formula (using BAC) indicates the performance needed to stay within the original budget.
The second formula (using EAC) shows the performance needed to meet the revised cost estimate.
Interpreting TCPI Values:
- TCPI = 1: The remaining work must be performed at the planned efficiency rate to stay on budget
- TCPI > 1: Greater efficiency than planned is required (difficult to achieve)
- TCPI < 1: Lower efficiency than planned is acceptable (easier to achieve)
As a rule of thumb:
- TCPI values between 0.9 and 1.1 are generally achievable
- TCPI > 1.2 indicates significant risk, as substantial efficiency improvement is rarely sustainable
Practical Example:
Consider a project with:
- BAC = $100,000
- EV = $40,000
- AC = $50,000
TCPI = (100,000 - 40,000) / (100,000 - 50,000) = 60,000 / 50,000 = 1.2
This means the team must perform at 20% higher efficiency than planned on the remaining work to stay within budget—a challenging proposition that requires immediate attention.
Exam Tips: Answering Questions on TCPI
1. Calculation Accuracy
- Double-check which formula you should use (BAC-based or EAC-based)
- Pay attention to the units and ensure all values are in the same units
- Verify your arithmetic, especially when calculating under time pressure
2. Conceptual Understanding
- Remember that TCPI measures required future performance, not past performance
- Understand the relationship between TCPI and other earned value metrics (CPI, SPI)
- Be clear about what each value (>1, =1, <1) indicates for project management
3. Application Questions
- For scenario-based questions, first identify all the variables provided (BAC, EV, AC, EAC)
- When asked about recommended actions, consider the magnitude of the TCPI (slight deviation vs. significant deviation)
- Connect TCPI values to appropriate management responses (continue as planned, minor adjustments, major intervention)
4. Common Exam Traps
- Mixing up the formulas for TCPI, CPI, and SPI
- Interpreting the meaning of values incorrectly (i.e., thinking TCPI > 1 is good news)
- Using the formula with BAC when the question scenario requires using EAC
5. Practice Strategies
- Memorize the formulas and practice calculations with different scenarios
- Create a quick reference sheet with formulas during exam prep
- Work through examples where you calculate TCPI at different project stages
By mastering the TCPI concept, formula, and interpretation, you'll be well-prepared for exam questions on this important project management metric.